This invention relate to an arrangement for storing elements, particularly optical fibers and/or optical fiber splices, within a splice closure.
Storage arrangements are used in splice closures in the joining of optical fiber cables. The splice closure is used to provide environmental protection and sealing of the joint in e.g. telecommunications and data transmission networks, which joints are formed either between cables or at the termination of a cable to terminal equipment.
The conventional arrangement for storing optical fibers at a joint to ensure a high degree of protection during the jointing process is to insert the fiber into a tray or attach it to a plate. The trays or plates are then stacked one above the other in a cassette stacking arrangement. The tray or plate either singular or multiple is positioned inline with the cable entry ports.
This arrangement has various disadvantages. For example, splice closures are generally cylindrical in shape to improve sealing performance and ease of re-entry. However, cylindrical shape closures doe not allow the maximum use of available space when stacking a multiplicity of trays in line with the cable entry ports. In order to ensure that the required number of trays can be fitted without increasing the outside diameter of the closure, the width of tray has to be reduced. The arrangement when viewed from the side (at 90 degrees to cable entry), involves fitting a rectangular mass into a cylindrical cavity and requires a reduction in the width of the tray or plate, reducing the maximum bend radius which is available for the fiber within the tray or plate, and so introducing a degree of light loss through the wall of the fiber. It is desirable to maintain as large a bend radius as possible for the optical fiber, to minimize the losses and improve the operating efficiency of the network.
Inline cassette arrangements have the further disadvantages of limiting the height of the stack of trays and limiting the space available within the joint for the free passage of excess fibers or fiber carrying tubes around the jointing space over the entire length of the joint.